1. Field of the Invention
The present invention is related to an auxiliary focusing tool for a laser marker, and especially to such a simple auxiliary focusing tool able to accurately and fast adjust the focal distance between a laser focal lens and a work piece, it suits engraving equipments such as laser markers.
2. Description of the Prior Art
Marks for conventional industrial products are tags made by corrosion, photoelectric processing, mechanical carving and die punching etc., they have inferior accuracy, and are subject to deformation, efficiencies of the articles obtained from which are low and speed of processing is slow, the dies for them are subject to damage and need frequent changing; if the products are numerous in their amount, serial numbers or specifications, the dies for the tags need changing to more increase cost.
In the initial stage of the years of eighties, a brand new technique of application in lasing (laser mark-marking technique) was developed quietly in the world; the technique is an accomplishment resulted from modern high scientific techniques including the laser technique and the computer technique; when articles of plastic, rubber or mechanical parts, or of electronic devices, instruments, tools etc. are to have their surfaces given markings composed of letters, patterns etc., in contrary to conventional mechanical engraving, chemical corrosion, silk-net printing, ink printing etc., the laser mark-marking technique has the features of wide scope of application, high accuracy and efficiency of marking, capability of being controlled with a computer, non-limitation of life of use by fatigue induced by marking as is the case of a conventional die, and firmness as well as permanence of the markings made on the work pieces by laser action.
Generally, when laser beams are irradiated on a work piece 3 for marking, the focal point of the output light source shall be adjusted to get the best effect of processing, the laser markers available presently are mutually different in their scope of processing in pursuance of their mutually different specifications of lenses for focusing. The focal lengths of the different specifications of lenses for focusing are also mutually different; thereby, before laser marking, a measuring tool such as a meter 1 must be used to measure the distance between a laser marker 2 and the work piece 3. As shown in FIG. 1, for example, with a given output lens, the work piece 3 must have a distance 10 cm from the laser marker 2 as the focal length; in processing, a tool such as the meter 1 or a block gauge must be used to get the distance 10 cm by measuring between the laser marker 2 and the work piece 3 and then the work piece 3 is gradually adjusted and positioned before starting the process of laser marking. However, there is no effective measuring tool on conventional laser markers, operators generally measure focal distances with meters 1 on their hands; when the shapes of the surfaces of work pieces 3 are irregular or thickness of the work pieces 3 is different, this measuring mode is hard to be used normally and is subject to making errors to make outputs 4 of the laser light sources onto the work pieces 3 too deep or too shallow to thereby make flaws on the products.
In view of these, the inventor of the present invention developed the present invention based on his experiences of years after hard study to get rid of the conventional defects.